Fortum last week said it has installed a lithium-ion battery storage system in conjunction with its biomass plant in Jarvenpaa, Finland.

Called the “battery cave,” or Batcave, project, the energy storage system has a nominal output of 2 MW and energy capacity of 1 MWh. The battery includes about 6,600 lithium-ion cells and offers second- and minute-level grid flexibility in frequency regulation, the company said.

“Our Batcave project takes us a big step closer towards the solar economy, where electricity storage plays an important role alongside renewable energy production forms,” Tatu Kulla, head of business development, Fortum, said. “The electricity battery brings flexibility to the national electricity market, benefitting all electricity users. In addition to storing electricity, the Batcave project allows us to test completely new ideas for optimal control of the battery together with other flexible electricity production forms.”

Fortum said that the cost to develop the Batcave project is about 1.6 million euros (US$1.7 million), and the company will receive a 30 percent energy investment subsidy from the Ministry of Economic Affairs and Employment. The energy storage system was supplied by French battery provider SAFT.